IC tester socket

ABSTRACT

An IC tester socket comprises a spring for keeping the socket body and the spacer frame in their state of being spaced apart from each other with a predetermined interval; and contacting pins each having a spring portion shaped in a pair of arcuate forms, in order to ensure the contact between the lead terminals of an IC requiring testing and the contacting pins to be realized positively and stably and to make it possible for the socket to stand its use for a prolonged period of time. The arm of each contacting pin which is brought into contact with the side face to its mating lead terminal of the IC is adapted to contact the side face of the lead terminal, and is so shaped as to be able to lock the IC package at the position of contact of this arm.

BACKGROUND OF THE INVENTION

(a) Field of the invention:

The present invention relates to an improvement of the IC tester socketwhich is suitable for use in the performance test of a flat type IC(Integrated Circuit) having curved lead terminals and like testing.

(b) Description of the prior art:

Flat type IC tester sockets have been constructed in the past so that,as shown in FIG. 1, by urging, via an urging member A, the bottom faceRF of a lead terminal R of an IC package (note: in actual practice, aface connected to, for example, the circuit line of the printed circuitboard) to a top face CF for contact of a contacting pin C attached to anelectrically insulated socket body B, the connection of the leadterminal R with the contacting pin C is established.

With the above-mentioned structure, however, the contact face RF of thelead terminal R of the IC package P tends to be injured easily, andmoreover there occurs deposition of dust onto this contact face, andfurthermore, dust could fill in the space existing therearound. In sucha case, it should be noted that, in a compact-size IC package P, thepitch size between adjacent lead terminals R is very small, andaccordingly it is difficult to easily remove the dust which hasdeposited onto the lead terminal portions. Especially, in case of suchdust that cannot be found with the naked eye, there would arise the riskthat the IC package bearing unnoticeable dust is shipped as being anacceptable product in the performance test. However, when, in actualpractice, such an IC package as mentioned above is mounted on a printedcircuit board and soldered, it would cause poor soldering, or even whenthe IC package is soldered once to the printed circuit board, thesoldered portion would come off at a later date and develop a disorderin the connection, causing the IC-mounted hardwares to becomeinoperative. Also, in such a case as mentioned above, it is the generaltrend that the circuitry is compact in size and complex, so that it isextremely difficult to check and find the bad spot, and a lot of time isrequired for inspection. In order to preliminarily prevent such disorderand trouble from taking place, a close inspection step has to beintroduced before the assembling step.

In order to solve the above-mentioned problems, there has been proposeda tester socket which is constructed so that the contacting pins arebrought into contact with the side faces of the lead terminals (U.S.Pat. No. 4,491,377). FIGS. 2A and 2B show an example of such a testersocket. More particularly, the contacting pin C has its upper portionmade in a bifurcated fork shape and has a downwardly and inwardlyextending slant top face C₁, and has its lower portion inserted in thesocket body B. An urging member A, when viewed from thereabove along thearrow in FIG. 2A, is of a square frame shape whose central portion isopen, and is attached to the socket body B via guide columns G forvertical movement. Inside this urging member A, there is formed aninclined face A₁ which is brought into a sliding contact with the slanttop face C₁ of the contacting pin C. This contacting pin C is flat inshape and is so made that elastic force acts upon it in a direction tocause the respective arms of its bifurcated fork portion to part awayfrom each other. The magnitude of the elastic force is selected to be inthe level of being able to hold the urging member A in its position ofFIG. 2A against its own gravity in the relaxed position thereof in FIG.2A. FIG. 2A shows the state that an IC package P which requires testingis placed in position through the central opening or cavity of theurging member A. In this state, by downwardly pushing the urging memberA in the direction of the arrow, the slant top face C₁ of the contactingpin C is urged by the inclined face A₁ of the urging member A, causingthe inner arm of the fork thereof to be displaced to the tensionedposition of FIG. 2B. As a result, the IC package P drops onto theposition it is received by the socket body B and rests thereat. In thisstate, by relieving the urging force applied to the urging member A, thetensioned fork arm tends to return to its relaxed position by its ownrestoring force. However, because the side face C₂ of the fork arm is inpressure-contact with the side face R₁ of the lead terminal R, the forkarm is forced to stop in this position, and accordingly the IC package Pis rendered to the state of being nipped at both sides by the contactingpins C. Thus, when various kinds of test have been completed, the urgingmember A is pressed downwardly again. Whereupon, the IC package P can betaken out easily. By subsequently releasing the pressure applied to theurging member A, both the contacting pins and the urging member restoretheir respective positions shown in FIG. 2A.

Now, sockets of this type, in general, are small in the size of thewhole body and accordingly the contacting pins are made thin and smallin size. The conventional socket having the above-described improvedsturuture is of such an arrangement that a markedly heavy load is forcedto be applied to a portion of the contacting pin, i.e. a structure thatone of the fork arms of the respective contacting pins is forced toexert the following two functions, one of which is to support the urgingmember and the other is to hold the contact pressure applied to themating lead terminal. Hence, there is the drawback that the contactingpins tend to become fatigued easily, and that according they cannotstand their use for an extended period of time. In other words, when thebase portion of the fork arm becomes fatigued, it immediately developsmal-contact so that the tester socket will become unusable. Also, in thetester socket having the abovedescribed conventional structure, itscontact pins do not have a configuration which makes it possible tomaintain a sufficient and proper elastic force.

SUMMARY OF THE INVENTION

It is, therefore, a primary object of the present invention to providean IC tester socket having contacting pins arranged to be able topositively and securely contact, under proper pressure, the side facesof the lead terminals of the IC and also to be reduced of the loadapplied to the contacting pins per se to thereby be able to stand theiruse for a prolonged period of time.

Another object of the present invention is to provide an IC testersocket which is very safe and displays a high degree of performancebecause of the arrangement that the contact between the contacting pinsand the lead terminals are positively established so as to allow an ICpackage to be mounted in either the normal or the upside-down postureand also that, when the socket body is inverted, the mounted IC packagewill never drop out of the socket.

A further object of the present invention is to provide an IC testersocket which allows an IC package to be smoothly and snugly seated inthe predetermined position in the socket without requiring a specialattention at the time the IC package is mounted.

Still another object of the present invention is to provide an IC testersocket which eliminates the occurrence of poor contact due to theshifting of the positions at which the contact pins are provided and theoccurrence of poor contact due to the wear of the spring portions of therespective contacting pins.

These and other objects as well as the features and the advantages ofthe present invention will be apparent from the following detaileddescription of the preferred embodiments when taken in conjunction withthe accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an explanatory illustration of the state of use of an exampleof the conventional IC tester socket.

FIG. 2A is a vertical sectional view showing another example ofconventional IC tester socket in its normal state.

FIG. 2B is a partial sectional view showing the IC testing state by theIC tester socket shown in FIG. 2A.

FIG. 3 is an exploded perspective view showing the overall structure ofan IC tester socket according to the present invention excluding thecontacting pins.

FIG. 4 is a side elevation, partly broken away, showing a firstembodiment of the IC tester socket according to the present invention.

FIGS. 5A, 5B and 5C are diagrammatic partial sectional views forexplaining the functions of the socket shown in FIG. 4.

FIG. 6 is a sectional view of the essential portion showing an secondembodiment of the IC tester socket according to the present invention.

FIG. 7 is an explanatory illustration showing the state of contactbetween the lead terminals of the IC package mounted in its normalposition and the contacting pins in the embodiment of FIG. 6.

FIG. 8 is an explanatory illustration showing the state of contactbetween the lead terminals of the IC package mounted in its upside-downposture and the contacting pins in the embodiment of FIG. 6.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

By first referring to FIGS. 3 and 4, description will be made of thegeneral structure of the IC tester socket according to the presentinvention. This IC tester socket is of the structure that, upon a squaresocket body 1, a spacer frame 2 and an urging cover 3 both having thesame shape as that of the socket body 1 are superposed. The spacer 2 andthe urging cover 3 are attached by screws 4 and nuts 5 provided at fourcorners of these respective members so as to allow the vertical movementthereof. The socket body 1 is provided, on the respective sides of thesquare body, with contacting pins 6 (FIG. 4) extending outwardly fromthe body in parallel with each other and at predetermined intervals. Thespacer 2 and the urging cover 3 are normally separated away from thesocket body 1 by means of springs 9 loosely mounted on cylindricalportions 7 which are provided at the four corners of the spacer 2 andwhich are loosely inserted through bores 8 provided through the fourcorners of the socket body 1. The upper face of each bore 8 is providedwith an upper recess 10 intended for seating its mating spring 9, andbetween two such upper recesses 10 and 10 is provided a cut-out havingan L-shaped cross section, and grooves 12 for receiving contacting pins6 are provided in a row n the lower face of the cut-out 11, and an airpassageway opening or cavity 13 for cooling is provided centrally ofeach of the three members 1, 2 and 3.

The spacer 2 is a frame having an external configuration which is thesame as that of the socket body 1. This spacer frame 2 is provided, atits four corners, with bores 14 (FIG. 4) for the passage therethrough ofscrews, and from the underside of these bores 14 protrude the cylinderportions 7 which are intended for mounting the springs 9 thereon,respectively. The base portions of these cylindrical portions 7 areprovided with circular recesses 15 to serve as the receiving saucers forsaid springs 9. Also, in each of the four inner sides of this spacerframe 2 are provided a row of cut-outs 16 for the insertion therein offirst arms 6-1 of the contacting pins 6, respectively. At the bottom ofthese cut-outs 16 of each row is formed a jetty 17 intended to urge saidfirst arms 6-1 of the contacting pins 6, and at both ends of this jettyare provided guide plates 18, 18, respectively. Also, at the fourcorners of the spacer 2 are provided corner portions 19 hvaing anL-shaped cross section, formed to match the external configuration ofthe IC package P, and on the upper face of the spacer 2, along each ofthe four sides of this spacer, there is provided a jetty 20.

The urging cover 3 is comprised of a frame similar to the spacer frame2, and has bores 21 formed at the four corners thereof for the passageof screws 4 therethrough. On the inner sides of the bottom face of theurging cover 3 are provided but-outs 22 for the insertion therein ofsecond arms 6-2 of the contacting pins 6, respectively, and on theunderside of the four sides of this urging cover 3 are provided grooves23, respectively, for the insertion therein, for positioning, of thejetties 20 of said spacer 2, and at the inner four corners of the spacer2, there are provided slant-faced corner portions 24 which contact thecorner portions 19 of the spacer 19, respectively.

In this instant embodiment, the spacer 2 and the urging cover 3 arefixed together by means of the screws 4. It should be noted here that,instead of the above-mentioned structure, these two members 2 and 3 maybe molded as an integral body to serve as a single urging member. Itshould be noted here also that, in this embodiment, the socket body 1,the spacer 2 and the urging cover 3 are invariably produced byextrusion-molding of PPS resin as the constituting material of thesemembers.

Next, description will be made in detail of the abovesaid contactingpins 6. The contacting pin 6 is made by plating a punched thin flatmetal plate having an appropriate elasticity. It comprises a firstspring porton 6-4 which is curved to have a substantially round shapeand which extends above and contiguous from the leg portion 6-3 which isinserted in a groove 12 of the socket body; a second spring portion 6-5extending from the foremost end of said first spring portion 6-4 andbeing curved in a direction opposite to the direction of the curve ofsaid first spring portion 6-4; said first arm 6-1 extending from a sitebetween said first spring portion 6-4 and said second spring portion 6-5and being urged by said jetty 17 of the urging cover 3; and said secondarm 6-2 extending from the foremost end of the second spring portion6-5.

Next, description will be made of an example of assembly of the ICtester socket. To begin with, the contacting pin 6 is inserted in themating groove 12 of the socket body 1 in such a way that the second arm6-2 of the contacting pin 6 is positioned on the inner side of thegroove 12. Next, the jetty of the spacer 2 is inserted in the groove 23of the urging cover 3 for engagement therewith, and these two members 3and 2 are placed one upon another. In this state, the cylindricalportion 7 of the spacer 2 is fit in the vertical opening of thecoil-shaped spring 9 whose lower portion rests in the upper recess 10provided on the socket body 1, and along therewith said cylindricalportion 7 is inserted into the bore 8. As a result, the second arm 6-2of the contacting pin 6 becomes loosely inserted in the cut-out 22 ofthe urging cover 3 and along therewith the first arm 6-1 of thecontacting pin 6 becomes loosely inserted into the cut-out 16 of thespacer 2. Subsequently, the screw 4 is passed through the bore 21 of theurging cover 3, the bore 14 of the spacer 2 and through the bore of thecylindrical portion 7, and then the screw 4 is threaded through the nut5 which is provided in the recess 1a of the bottom face of the socketbody 1 to thereby unite the socket body 1 to the spacer 2 and to theurging cover 3 together.

Next, description will be made of the mounting of an IC package. InFIGS. 5A to 5C, it will be noted that, in the normal state of theassembly, the first arm 6-1 of the contacting pin 6 is urged by thejetty 17 of the spacer 2 as shown in FIG. 5A, so that the first springportion 6-4 is urged to curve further from its relaxed position, whilethe second arm 6-2 is inclined inwardly than the position of the leadterminal R of the IC package P which is to be mounted. In this state,let us assume that the IC package P is mounted, with its front sidefacing downward. Whereupon, the bent portion at the base of the leadterminal R is brought to a halt in its state of being in contact withthe second arm 6-2 of the contacting pin 6. In this case, the horizontalposition of the IC package P is restricted by the corner portions 19located at four corners of the spacer 2, so that the lead terminal Rwill be rendered to be placed exactly on the second arm 6-2. Next, asshown in FIG. 5B, the urging cover 3, together with the spacer 2, ispushed downwardly toward the socket body 1 against the force of thespring 9. Whereupon, the jetty 17 of the spacer 2 also moves downwardlyto relieve the first arm 6-1 of its applied pressure, so that the secondarm 6-2 is caused to move outwardly due to the restoration of the firstspring portion 6-4 back to its relaxed state. As a result, the ICpackage P drops downwardly by its own gravity until it contacts thesocket body 1. This state is shown in FIG. 5B, wherein the first andsecond spring portions 6-4 and 6-5 are both in their relaxed state.Next, when the pressure having been exerted by the urging cover 3 islifted as shown in FIG. 5C, the urging cover 3, together with the spacer2, restores the state which they had prior to application of pressure,due to the restoring force of the spring portion 9 which is providedbetween the socket body 1 and the spacer 2. This state, alike the stateshown in FIG. 5A, is such that the first arm 6-1 is urged by the jetty17 to cause tension of the first spring portion 6-4, and along therewiththe second arm 6-2 moves inwardly to contact, with a relatively largearea of its own, the side face of the lead terminal R, and alongtherewith that portion of the second arm which would move furtherinwardly remains as an urging force for the second spring portion 6-5.Therefore, the contact becomes positive, and also the contact resistanceis reduced.

In order to take the IC package P out of the assembly, it is onlynecessary to establish the state of assembly as shown in FIG. 5B and toinvert the posture of the socket, or to such the IC package P by meansof, for example, a vacuum pincette.

As will be clear from the foregoing description, in the IC tester socketof the present invention, no contact takes place on the solderedjunction regions of the lead terminals R of the IC package P, so thatthere arises no contamination or injury of the soldered faces, thusmaking it possible to eliminate unsuccessful connection when the ICpackage P is mounted on a hardware in actual practice. Also, at the fourcorners of the spacer frame 2, there are provided the corner portions 19for positioning purpose. Thus, the mounting of the IC package P onto thesocket body 1 can be performed smoothly without causing unstablemovements, and there is needed no particular attention to be paid at thetime it is mounted in the socket. Furthermore, the normal state(pushed-up state) of the spacer frame 2 and the urging cover 3 ismaintained by the force of the springs 9, and the contacting pins 6 donot take part in the pushing-up of the spacer frame 2 and the urgingcover 3. Thus, when compared with the above-described conventionalsystems, the load applied to the contacting pins can be markedlyreduced, with the result that there can be provided a socket of thistype which is capable of standing the use for a prolonged period oftime. Also, the second arm 6-2 is formed via the second spring portion6-5 which is separate from the first spring portion 6-4, and accordinglythe second arm 6-2 is able to contact the lead terminal R morepositively and more exactly, an in addition, it is possible to eliminatethe mal-contact due to the shifting of the position of mounting thecontacting pin 6 and also to the wear of the spring portion of thecontacting pin 6.

FIGS. 6 to 8 show a second embodiment of the IC tester socket accordingto the present invention. In this instant embodiment also, the generalconfiguration of the IC socket as a whole is substantially the same asthat of the above-described first embodiment. Thus, the detaileddescription of this second embodiment is omitted here, and those partsand portions same as those of the abovementioned embodiment are assignedwith identical numerals and symbols. Only the essential portions of thestructure will be described in detail. According to the IC tester socketof this latter embodiment, the second arm 6-2 of the contacting pin 6 isprovided with the formation of a slant face 6-2-1 serving as a firstcontacting portion which is inwardly slanted relative to the side faceof the IC package P which is placed at its mounting position, and alsowith the formation of a hook 6-2-2 serving as a second contactingportion projecting inwardly. As shown in FIG. 7, in case the IC packageP is mounted in its normal posture on the socket body 1, the abovesaidslant face 6-2-1 is brought into contact with a first bent portion R₁ ofthe lead terminal R and mating two of these slant faces nip the ICpackage P at both sides thereof while urging the package downwardly.Also, when the IC package P is mounted in its upside-down posture asshown in FIG. 8, the second bent portions R₂ of the lead terminals R arecontacted by the hooks 6-2-2 so that the IC package P is nipped at bothsides thereof. In this second embodiment also, it will be noted that, bypushing the urging cover 3 downwardly against the force of the spring 9(FIG. 3), the jetty 17 will be caused to descend so that the first andsecond arms 6-1 and 6-2 of the contacting pin 6 will move outwardly tothe position indicated by the chain line in FIG. 6 due to their ownrestoring forces, with the result that, when an IC package P is to bemounted, the IC package which has been set in its predetermined positionwill drop and it is brought into contact with the surface of the socketbody 1, and thus it is automatically mounted. Next, by relieving thedownward urging force exerted by the urging cover 3, the jetty 17 iscaused to ascend by the spring force of the spring 9, and accordinglythe first arm 6-1 is urged to move inwardly. This movement of the firstarm 6-1 is followed by the movement of the second arm 6-2 up to theposition indicated by the solid line, so that when the IC package P ismounted in its normal posture, the opposing slant faces 6-2-1 of thesecond arms 6-2 are brought into contact with their mating leadterminals R to thereby nip the IC package, whereas when the IC package Pis mounted in its inverted posture, the hooks 6-2-2 of the second arms6-2 and the upper end portions of the slant faces 6-2-1 are brought intocontact with the lead terminals R to nip the IC package, and thus themounting of the IC package P onto the IC tester socket completes.

As will be clear from the foregoing description, when the IC package Pis mounted in its normal posture, the first bent portions R₁ of the leadterminals R are nipped in their downwardly urged state by the slantfaces (the first contacting portions) 6-2-1 and 6-2-1. Accordingly, notonly the contact between the lead terminal R and the second arm 6-2 isperformed positively, but also there is another advantage that, evenwhen the IC socket is invertedthe IC package P is positively heldwithout causing the drop-out of this package. Also, when the IC packageP is mounted in its upside-down posture, the lead terminals R are nippedin such a state that their second bent portions R₂ are nipped in itsstate of being in contact with the hooks 6-2-2. Therefore, similarly tothe above case, even when the IC socket is inverted, the IC package P ispositively anchored without dropping off the socket. At the same time,there is the further advantage that, due to the contact between the leadterminal R and the upper end portion of the slant face 6-2, there isobtained a better electrical connection. It should be noted here that,while in this instant embodiment, the lead terminal R is formed in anarcuate shape (C-shape), the configuration thereof is not limitedthereto, the IC tester socket of the present invention can be used aswell in the testing of IC package having lead terminals of such a shape(J-shape) as shown in FIG. 1, and also in the testing of those ICpackages provided with lead terminals of various other curved shapes. Itis needless to say that, in the above-mentioned second embodiment, thepresent invention provides also the advantages similar to those obtainedin the first embodiment.

What is claimed is:
 1. An IC tester socket, comprising:a socket body; anumber of contacting pins, each having a first spring portion of apredetermined resiliency and each extending from said socket body, thecontacting pins being arranged to flex inwardly and outwardly relativeto a central portion of the socket body and to mate respectively with anumber of lead terminals of an IC package to be tested; an urgingmember, mounted on said socket body for vertical movement above thesocket body, the urging member having defined in its central portion, acavity capable of accommodating said IC package and further having,along its peripheral portions, a number of jetties engaged respectivelywith said number of contacting pins in such a manner wherein the jettiescan urge the contacting pins to flex inwardly while placing the firstspring portion of each corresponding contacting pin in a strained statewhen the contacting pin is flexed inwardly; and at least one spring,interposed between said socket body and said urging member, forelastically urging said socket body and said urging member to normallypart away from each other with a predetermined interval therebetween,wherein each of said contacting pins is provided with a leg portionfixedly inserted in said socket body, the first spring portion is formedabove said leg portion in an arcuate shape and is contiguously joined tosaid leg portion, and wherein each of said contacting pins is furtherprovided with: a second spring portion, joined contiguously to saidfirst spring portion at a junction site and formed in an arcuate shapebulging in a direction opposite to the arcuate shape of said firstspring portion; a first arm extending in a direction opposite to saidleg portion from the junction site of said first spring portion and saidsecond spring portion to engage its mating jetty so that the matingjetty can push inwardly aginst the first arm and thereby urge thecontacting pin to flex inwardly; and a second arm contiguously joined tosaid second spring portion and extending in a direction opposite to saidleg portion for being brought into contact with its respective matinglead terminal of said IC package, such that when said urging member ispushed downwardly against the force of said at least one spring, thefirst spring portion of each of said contacting pins is relieved atleast partly from the strained state in which its corresponding firstarm is pushed by a corresponding one of said jetties, to allow outwardmovement of each of said contacting pins by the resiliency of theircorresponding first spring portions so that said IC package may beaccommodated into said cavity, and such that when the downward push onsaid urging member is relieved, said urging member is restored to itsnormally parted position relative to the socket body by said spring,said first arm is pushed inwardly by a corresponding one of saidjetties, and said contacting pins are urged to flex inwardly against theresiliency of the first spring portion and to contact the lead terminalsof said IC package which has been accommodated in said cavity.
 2. An ICtester socket according to claim 1, in which:said second arm is providedwith a first contacting portion for uging a first bent portion of itsmating lead terminal of said IC package accommodated in said cavity, andwith a second contacting portion for urging a second bent portion ofsaid lead terminal, whereby said IC package is adapted to be locked tosaid socket body by said first and second contacting portions.
 3. An ICtester socket according to claim 2, in which:said first contactingportion is formed with a slant face inclined relative to a side face ofsaid IC package, and said second contacting portion if formed with ahook.
 4. An IC tester socket according to claim 1, in which:said urgingmember is provided with corner portions for positioning said IC packageaccommodated in said cavity.
 5. An IC tester socket according to claim1, in which:said urging member comprises an urging cover and a spacerframe which can fit one into the other.
 6. An IC testing socketcomprising:a socket body having a central top portion which has a chipaccommodating space defined thereabout for accommodating an IC packageof predetermined dimensions; a contacting pin, made of a resilientmaterial and having: (a) a base portion fixedly secured in the socketbody, (b) a lead contacting portion disposed to be positioned out of thechip accommodating space in a first mode and to move inwardly toward thechip accommodating space while straining the resilient material of thecontacting pin in a second mode, (c) an intermediate portion locatedbetween the base portion and the lead contacting portion, (d) a jettyengaging portion extending from the intermediate portion, and (e) afirst arcuate spring portion interposed between the base portion and theintermediate portion; and an urging member, movably disposed adjacent tothe socket body, the urging member including a jetty that slidablyengages with the jetty engaging portion so that (a) when the urgingmember is moved to a first position, the jetty will push against thejetty engaging portion to thereby urge the lead contacting portion tomove inwardly toward the chip accommodating space against the resiliencyof the first arcuate spring portion and (b) when the urging member ismoved to a second position, the jetty will be relieved from pushingagainst the jetty engaging portion at least partly to thereby allow thelead contacting portion to move outwardly of the chip accommodatingspace.
 7. The IC testing socket of claim 6 wherein the contacting pinfurther includes a second arcuate spring portion interposed between theintermediate portion and the IC lead contacting portion.
 8. An IC leadcontacting pin for an IC testing socket which includes a verticallymovable jetty, comprising:a base portion which is vertically disposedfor vertical insertion into a base portion of the IC testing socket; afirst C-shaped portion having first and second ends of its C-shape, thefirst end of the first C-chaped spring portion being integrallyconnected to the top of the base portion; a second C-shaped springportion having first and second ends of its C-shape, the second end ofthe second C-shaped spring portion being connected to the second end ofthe first C-shaped spring portion to form a generally S-shapedconfiguration; an IC lead contacting terminal, extending vertically fromthe first end of the second C-shaped spring portion; and a jettyengaging arm, extending at an incline from the second end of the secondC-shaped spring portion such that the jetty engaging arm can engage withthe vertically movable jetty to squeeze together or release the ends ofboth the first and second C-shaped spring portions.
 9. An IC testingsocket having a chip accomodating space defined therein for accomodatinga vertically insertable IC chip having a plurality of terminals,comprising:a socket body; a contacting pin extending from the socketbody and including: (a) a base portion secured to the socket body, (b) acontact portion disposed to move toward and away from the chipaccomodating space to respectively mate and unmate with a correspondingterminal of the IC chip, (c) a first arcuate spring portion coupling thecontact portion to the base portion so as to resiliently urge thecontact portion away from the chip accomodating space; (d) a junctionportion interposed between the contact portion and the first arcuatespring portion, (e) a second arcuate spring portion interposed betweenthe junction portion and the contct portion, and (f) an actuator armextending from the junction portion so as to be engaged by the actuatingmeans; and actuating means, engageable with the contacting pin, forovercoming the resiliency of the first arcuate spring portion and movingthe contact portion of the contacting pin toward the chip accommodatingspace.
 10. An IC testing socket according to claim 9 wherein theactuator arm includes an inclined portion and the actuating meansincludes a vertically movable jetty that engages against the inclinedportion.